XB402U-L27

XB402U SC74-6 1 LED Driver 1.1 Features • • • • • • • • • • LED drive current preset to 20 mA Output current adjustable up to 65 mA with an external resistor Easy paralleling of drivers to increase current Supply voltage up to 40 V High current accuracy at supply voltage variation Low voltage overhead of 1.4 V Up to 750 mW power dissipation in a small SC74 package Negative thermal coefficient of -0.2 %/K reduces output current at higher temperatures RoHS compliant (Pb-free) package Automotive qualified according AEC Q101 1.2 • • • • • Applications Channel letters for advertising, LED strips for decorative lighting Aircraft, train, ship illumination Retrofits for general lighting, white goods like refrigerator lighting Medical lighting Automotive applications like CHMSL and rear combination lights 1.3 General Description The XB402U is a cost efficient LED driver to drive low power LEDs. The advantages towards resistor biasing are: • • • • homogenous light output despite varying forward voltages in different LED strings homogenous light output of LEDs despite voltage drop across long supply lines homogenous light output independent from supply voltage variations longer lifetime of the LEDs due to reduced output current at higher temperatures (negative thermal coefficient) The advantages towards discrete solutions are: • • • • lower assembly cost smaller form factor higher reliability due to less soldering joints higher output current accuracy due to pretested LED drivers Dimming is possible by using an external digital transistor at the ground pin. The XB402U can be operated at higher supply vo ltages by putting LEDs between the supply voltage VS and the power supply pin of the LED driver. You can find further details in our application notes. The XB402U is a perfect fit for numerous low power LED applications by combining small form factor with low cost. These LED drivers offer several advantages to resistors like significantly higher current control at very low voltage drop ensuring high lifetime of LEDs. 1 XB402U SC74-6 Pin Configuration Typical Application +VS 4 VS 6 GND 1 6 Rex t OUT 2 5 OUT 3 4 Vdrop Rex t GND OUT Rex t (optional ) 1 OUT 2,3,5 IS Iout VS Figure 1-1 Pin configuration and typical application Sales Name XB402U Marking L279 Pin Configuration 1 = GND 2; 3; 5 = OUT 4 = VS 2 Package 6 = R ext SC74-6 XB402U SC74-6 2 Electrical Characteristics Table 2-1 Maximum Ratings at TA = 25 °C, unless otherwise specified Parameter Symbol Values Unit Min. Typ. Max. Supply voltage VS - - 40 V Output current Iout - - 65 mA Output voltage Vout - - 40 V Reverse voltage between all terminals VR - - 0.5 V Total power dissipation Ptot - - 750 mW Junction temperature TJ - - 150 °C Storage temperature range TSTG -65 - 150 °C Note / Test Condition TS ≤ 112.5 °C Attention: Stresses above the max. values listed here may cause permanent damage to the device. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Maximum ratings are absolute ratings; exceeding only one of these values may cause irreversible damage to the integrated circuit. Table 2-2 Thermal Resistance at TA = 25 °C, unless otherwise specified Parameter Symbol Values Min. Typ. Unit Note / Test Condition Max. Junction - soldering point1) 50 K/W RthJS 1) For calculation of RthJA please refer to Application Note AN077 (Thermal Resistance Calculation) Table 2-3 Electrical Characteristics at TA = 25 °C, unless otherwise specified Parameter Symbol Values Collector-emitter breakdown voltage VBR(CEO) 40 Supply current IS DC current gain Min. Unit Note / Test Condition Typ. Max. - - V IC = 1 mA, IB = 0 340 420 500 µA VS = 10 V hFE 100 220 470 - IC = 50 mA, VCE = 1 V Internal resistor Rint 38 44 52 Ω IRint = 10 mA Output current Iout 18 20 22 mA VS = 10 V Vout = 8.6 V Voltage drop (VRext) Vdrop 0.8 0.85 0.9 V Iout = 20 mA Table 2-4 DC Characteristics with stabilized LED load at TA = 25 °C, unless otherwise specified Parameter Symbol Lowest sufficient supply voltage overhead VSmin Values Unit Note / Test Condition Min. Typ. Max. - 1.4 - V Iout > 18 mA Output current change versusTA ∆Iout/Iout - -0.2 - %/K VS = 10 V Output current change versus VS ∆Iout/Iout - 1 - %/V VS = 10 V 3 XB402U SC74-6 3 Typical characteristics 1000 Ptot [mW] 800 600 400 200 0 0 20 40 60 80 TS [°C] 100 120 140 Figure 3-1 Total Power Dissipation Ptot = f(TS) RthJS [K/W] 100 10 D=0 D = 0.005 D = 0.01 D = 0.02 D = 0.05 D = 0.1 D = 0.2 D = 0.5 1 0.1 10-6 10-5 10-4 10-3 tp [s] Figure 3-2 Permissible Pulse Load RthJS = f(tp) 4 10-2 10-1 100 XB402U SC74-6 Ptotmax / PtotDC 1000 D=0 D = 0.005 D = 0.01 D = 0.02 D = 0.05 D = 0.1 D = 0.2 D = 0.5 100 10 1 10-6 10-5 10-4 10-3 tp [s] Figure 3-3 Permissible Pulse Load Ptotmax / PtotDC= f(tp) 5 10-2 10-1 100 XB402U SC74-6 Iout [mA] 100 10 1 Rext = open Rext = 75 Ω Rext = 24 Ω 0 5 10 15 20 25 VS [V] Figure 3-4 Output Current versus VS Iout = f(VS), VS - Vout = 1.4 V, Rext = Parameter 2 1.8 1.6 IS [mA] 1.4 1.2 1 0.8 0.6 0.4 80 °C 20 °C -40 °C 0.2 0 0 5 10 15 20 VS [V] 25 Figure 3-5 Supply Current versus VS IS = f(VS), TA = Parameter 6 30 35 40 XB402U SC74-6 25 Iout [mA] 20 15 10 1V 1.4 - 2 V 0 5 10 15 20 VS [V] 25 30 35 40 35 40 Figure 3-6 Output Current versus VS Iout = f(VS), VS - Vout = Parameter 25 Iout [mA] 20 15 10 5 0 -40 °C 20 °C 80 °C 0 5 10 15 20 VS [V] 25 30 Figure 3-7 Output Current versus VS Iout = f(VS), VS - Vout = 1.4 V, TA = Parameter 7 XB402U SC74-6 100 Iout [mA] -40 °C 20 °C 80 °C 10 10 100 Rext [Ω] Figure 3-8 Output Current versus R ext Iout = f( Rext), VS = 10 V, VS - Vout = 1.4 V, TA = Parameter 70 Rext = 18 Ω 60 Rext = 27 Ω Iout [mA] 50 Rext = 33 Ω 40 Rext = 56 Ω 30 Rext = 120Ω 20 Rext = open 10 0 -50 -25 0 25 50 TS [°C] 75 100 125 150 Figure 3-9 Output Current versus TS Iout = f( TS), VS = 10 V, VS - Vout = 1.4 V, R ext = Parameter 8 XB402U SC74-6 1.1 1.05 Vdrop [V] 1 0.95 0.9 0.85 typ. min., max. 0.8 10-5 10-4 IOUT [A] 10-3 10-2 Figure 3-10 Reference Voltage Vdrop vs Iout Vdrop = f(Iout), Iout = 10 µA to 10 mA 1 0.95 Vdrop [V] 0.9 0.85 0.8 0.75 0.7 0.65 0.6 typ. min., max. 10 20 30 40 IOUT [mA] 50 60 Figure 3-11 Reference Voltage Vdrop vs Iout Vdrop = f(Iout), Iout = 10 mA to 65 mA 9 70 XB402U SC74-6 4 Application hints +V S 4 VS Rex t (optional ) 6 Vdrop Rex t GND 1 OUT 2,3,5 IS I out Figure 4-1 Application Circuit: Stand alone current source +V S 4 VS 6 Rex t (optional ) Rex t GND 1 OUT Vdrop I LED 2,3,5 I out R1 R2 IS Figure 4-2 Application Circuit: Boost mode current source with external power transistor Application hints XB402U serves as an easy to use constant current source for LEDs. In stand alone application an external resistor Rext can be connected to adjust the current between 20 mA and 65 mA. Rext can be determinedby using Figure 3-8. Connecting a low tolerance resistor Rext will improve the overall accuracy of the current senseresistance formed by the parallel connection of Rint and Rext leading to an improved current accuracy. Please takeinto account that the resulting output currents will be slightly lower due to the self heating of the component andthe negative thermal coefficient. 10 XB402U SC74-6 5 SC74-6封装图 B 1.1 MAX. 5 4 1 2 3 0.35 +0.1 -0.05 Pin 1 2.5 ±0.1 6 0.2 M 0.25 ±0.1 0.15 +0.1 -0.06 (0.35) 1.6 ±0.1 2.9 ±0.2 (2.25) A B 6x 0.1 MAX. 0.95 marking 0.2 1.9 11 M A